Sen. Bernie Sanders (I-Vt.) has had a rough week, and it didn’t get any better when a former campaign volunteer accused Sanders’ campaign of taking credit for warning the Clinton campaign about Russia’s interference in the 2016 election and peddling a false story.

The volunteer, John Mattes, told Politico that he thought he alerted the Clinton campaign of the Russian efforts to prop up Sanders and hurt Clinton. However, Mattes never actually spoke to Clinton’s team–instead, he was in communication with a Political Action Committee supporting the Democratic nominee. Furthermore, Mattes said that he acted on his own and that Sanders’ staffers never directed him to alert Clinton.

Bernie’s bad week began last Sunday during an appearance on “Meet The Press.” On the iconic Sunday show, the lawmaker responded to a question about Russia’s efforts to support him by saying, “It turns out that one of our social media guys in San Diego actually went to the Clinton campaign in September and said something weird is going on.” It’s unclear if the staffer that he was referring to is Mattes. But again, Mattes told Politico that he confused the Clinton campaign with a PAC supporting her; he never actually went to the Clinton campaign.

On Wednesday, Sanders was interviewed on Vermont Public Radio where he muddled the issue even more. In that interview, the senator said that “a guy on [his] staff” alerted the Clinton campaign about Russian efforts to hurt Hillary. In the tense interview, Sanders was asked why he told his supporters that some of the pro-Bernie Facebook pages were the product of Russian propaganda efforts. In response, Sanders pointed to Mattes and seemed to take credit for directing the volunteer staffer to tip off Clinton’s team.

The VPR interview elicited a lengthy press release from Sanders’ office in which he said, “let there be no confusion on my view. What the Russians did during the 2016 election cycle deserves unconditional condemnation.”

Mattes says he doesn’t know why the senator told VPR and “Meet The Press” that the Sanders’ campaign was talking to Clinton’s team about Russian interference. The former campaign volunteer joked to Politico, “He could have called me…I’m going to send him a bill for my back pay.”

When asked by Politico why Sanders is peddling a false narrative, the senator’s spokesperson told the outlet, “[Bernie is] not a great fan of reporters who try to provoke controversy where none exist.”

Mattes says that he figured out that something suspicious was going on by doing some sleuthing on Facebook and reached out to the pro-Clinton PAC, American Bridge, thinking that they were in communication with Clinton’s team. But, American Bridge is not commenting on the conversations one of their staffers had with Mattes. There are strict campaign finance laws about dialogue between political action committees and campaigns.

The bad week could hurt Sanders down the road as he’s eyeing a presidential run in 2020 and is currently one of the front-runners in the field. While he hasn’t made any official moves, he’s certainly testing the water with a Labor Day visit to New Hampshire and a late January strategy session with a score of top political strategists.